The present invention relates to a tire with radial carcass reinforcement, and more particularly to the structure of the beads of the tire. It also relates to an assembly, formed by a tire and a rim, which rim is either monobloc with seats which may or may not be inclined, or in several sections, some of which are mobile, and possibly provided with a bearing support which may or may not be removable.
A tire with radial carcass reinforcement usually comprises, in known manner, a reinforcing bead wire in each bead, around which bead wire the carcass reinforcement is anchored by winding, forming an upturn. The characteristics of the bead wire, taken in combination with the meridian profile of the radially inner face of the bead and the meridian profile of the corresponding rim seat, ensure what is called the clamping of the bead on the rim. The clamping produces a certain compression of the portion of the bead between the bead wire and the bead seat, the clamping generally being brought about by a difference in the angles of the bead seat and the rim seat respectively, and/or by a difference in the diameters of said seats.
When such a tire is used on a rim having flat or inclined seats, with angles which may vary from 0.degree. to 30.degree., when the rim comprises a flat rim base and a plurality of mobile parts, when the rim is monobloc with a mounting groove, when the seats are inclined towards the inside or towards the outside, the clamping value of the beads on the rim seats, which clamping is necessary for solving the problems relating to the rotation on rim at the normal use pressure of the tire and for maintaining good lateral strength of the beads, becomes so great that difficulties are encountered in mounting such tires on their rims in practically all cases, even sometimes with the use of mounting presses.
Although these presses are common tools which are usual for tire manufacturers or motor vehicle manufacturers, they do not form part of the usual equipment of the garage mechanic who is usually approached when there is a problem relating to the tire, for instance a passenger-coach tire.